Waterline Disinfectants Reduce Dental Bioaerosols: A Multitracer Validation.

Oral microbes are dispersed during dental treatment and reduction methods have been proposed, but dental unit waterline (DUWL) disinfectants have received little attention; specifically, the effect on viruses has not been studied. This study aims to 1) investigate the effect of DUWL disinfectants on viral dispersion in dental bioaerosols and 2) establish a dual-tracer system using live bacteriophage and fluorescein supported by optical particle measurement. Bacteriophage MS2 was used as a viral tracer and fluorescein as a fluorescent tracer. Validation experiments were conducted to exclude interference of one tracer with the other or of DUWL disinfectants on detection methods. Simulated "saliva" containing the tracers was infused into the mouth of a dental mannequin during 10-min dental procedures with an air turbine handpiece (n = 3 replicates). Aerosols and droplets were sampled in an enclosed dental operatory using air samplers and settlement onto sterile filter papers. Bacteriophage was quantified using plaque assays and reverse transcription quantitative polymerase chain reaction (RT-qPCR). Fluorescein was quantified fluorometrically. The effect of DUWL disinfectants on total aerosol concentration was assessed in separate experiments using an optical particle counter. DUWL disinfectants reduced bacteriophage viability, and interference between tracers was not observed. In simulated clinical procedures, the disinfectant ICX reduced bacteriophage detection substantially (P < 0.001; 2-way analysis of variance). MS2 RNA was detected in all experimental samples but not negative controls. Samples positive on RT-qPCR but not plaque assays may indicate that virions at distant sites are nonviable. Fluorescein tracer showed good agreement with the bacteriophage tracer. DUWL disinfectants designed for continuous presence in irrigants reduce the dispersion of viable virus in dental bioaerosols during simulated procedures. Their use may therefore be important for routine infection control and as a mitigation factor during infectious disease outbreaks. Future studies should explore this using a range of viruses and other microbes.

Electronic cigarettes: an update on products, regulation, public health approaches and oral health.

BACKGROUND: Electronic cigarettes remain a divisive topic amongst public health experts and researchers. The division hinges on the the role of e-cigarettes in public health, i.e., whether e-cigarettes represent a potential to compromise decades of public health efforts by driving smoking rates up, or an effective tool to drive smoking rates down. Dental settings are a strategic place for stop smoking interventions, with large proportions of the population attending regularly and harms of smoking often presenting early in the mouth. Dental professionals should be equipped with the necessary information to provide evidence-based advice and recommendations to their patients. OBJECTIVE: To update dental professionals and researchers on the current regulations, public health approaches, and oral health effects of prevailing novel nicotine products, with a focus on e-cigarettes. METHODS: Narrative literature review. PRINCIPLE FINDINGS: Regulatory approaches vary considerably around the world but in the UK and Europe, e-cigarettes are regulated as consumer or medicinal product, and their use is permitted. In the UK, e-cigarettes have increasingly been supported by public health institutions for smoking cessation as part of a Tobacco Harm Reduction strategy. The potential harms (including to oral health) from e-cigarette use are likely to be much less than from tobacco cigarettes.

Local Exhaust Ventilation to Control Dental Aerosols and Droplets.

Dental procedures produce aerosols that may remain suspended and travel significant distances from the source. Dental aerosols and droplets contain oral microbes, and there is potential for infectious disease transmission and major disruption to dental services during infectious disease outbreaks. One method to control hazardous aerosols often used in industry is local exhaust ventilation (LEV). The aim of this study was to investigate the effect of LEV on aerosols and droplets produced during dental procedures. Experiments were conducted on dental mannequins in an 825.4-m3 open-plan clinic and a 49.3-m3 single surgery. Ten-minute crown preparations were performed with an air-turbine handpiece in the open-plan clinic and 10-min full-mouth ultrasonic scaling in the single surgery. Fluorescein was added to instrument irrigation reservoirs as a tracer. In both settings, optical particle counters (OPCs) were used to measure aerosol particles between 0.3 and 10.0 µm, and liquid cyclone air samplers were used to capture aerosolized fluorescein tracer. In addition, in the open-plan setting, fluorescein tracer was captured by passive settling onto filter papers in the environment. Tracer was quantified fluorometrically. An LEV device with high-efficiency particulate air filtration and a flow rate of 5,000 L/min was used. LEV reduced aerosol production from the air-turbine handpiece by 90% within 0.5 m, and this was 99% for the ultrasonic scaler. OPC particle counts were substantially reduced for both procedures and air-turbine settled droplet detection reduced by 95% within 0.5 m. The effect of LEV was substantially greater than suction alone for the air-turbine and was similar to the effect of suction for the ultrasonic scaler. LEV reduces aerosol and droplet contamination from dental procedures by at least 90% in the breathing zone of the operator, and it is therefore a valuable tool to reduce the dispersion of dental aerosols.

Electronic Cigarettes and Oral Health.

Novel nicotine products, particularly electronic cigarettes (e-cigarettes), have become increasingly popular over the past decade. E-cigarettes are sometimes regarded as a less harmful alternative to tobacco smoking, and there is some evidence of their potential role as a smoking cessation aid. However, there are concerns about their health consequences, particularly in users who are not tobacco smokers, and also when used long term. Given the mode of delivery of these products, there is potential for oral health consequences. Over the past few years, there have been an increasing number of studies conducted to explore their oral health effects. In vitro studies have reported a range of cellular effects, but these are much less pronounced than those resulting from exposure to tobacco smoke. Microbiological studies have indicated that e-cigarette users have a distinct microbiome, and there is some indication this may be more pathogenic compared to nonusers. Evidence of oral health effects from clinical trials is still limited, and most studies to date have been small in scale and usually cross-sectional in design. Epidemiological studies highlight concerns over oral dryness, irritation, and gingival diseases. Interpreting data from e-cigarette studies is challenging, given the different populations that have been investigated and the continual emergence of new products. Overall, studies reveal potential oral health harms, underscoring the importance of efforts to reduce use in nonsmokers. However, in smokers who are using e-cigarettes as an aid to help them quit, the benefits of quitting tobacco smoking may outweigh any negative oral health impacts of e-cigarette use, particularly in the short term. Future research is needed to understand the clinical significance of some of the biological changes observed by following different cohorts of users longitudinally in carefully designed clinical studies and pragmatic trials supported by high-quality in vitro studies.

Dental professionals' opinions and knowledge of smoking cessation and electronic cigarettes: a cross-sectional survey in the north of England.

Aims: To determine the current level of knowledge and opinions of UK dental professionals with regards to smoking cessation and e-cigarettes. Method: A self-administered online survey was distributed by postal invitation to all dental practices in the north of England registered on the National Health Service (NHS) Choices website. Findings: One hundred and ninety completed questionnaires were received. Seventy-nine percent of respondents reported always enquiring about the smoking status of their patients with 17% completing referrals to a specialist stop smoking service. Just under half of respondents reported not receiving any smoking cessation advice training. Lack of time during appointments, lack of training and lack of perceived interest by patients were reported as the most important barriers. The importance of a lack of remuneration, as a barrier, varied considerably with professional role. Approximately a third (31%) of respondents were of the opinion that e-cigarettes are more or equally harmful than cigarettes with the majority not aware of any guidance documents or recommendations regarding e-cigarettes. Conclusion: The majority of dental professionals in the north of England reported providing smoking cessation advice, although only half had training on this. Opinions on electronic cigarettes were mixed, with a third having negative views.

Developmental reversals in false memory: Development is complementary, not compensatory.

We report the 1st example of a true complementarity effect in memory development-a situation in which memory for the same event simultaneously becomes more and less accurate between early childhood and adulthood. We investigated this paradoxical effect because fuzzy-trace theory predicts that it can occur in paradigms that produce developmental reversals in false memory, which are circumstances in which adults are more likely than children to remember new events as old. The complementarity prediction is this: If subjects separately judge whether those same events are new but similar to old ones, adults will be more accurate than children, even though adults are less accurate when they judge whether the items are old. We report 4 experiments in which children (6- and 10-year-olds), adolescents (14-year-olds), and adults encoded the modal developmental reversal materials: Deese-Roediger-McDermott lists. Then, they responded to memory tests on which half the subjects judged whether test items were old and half judged whether the same items were new-similar. The paradoxical complementarity effect was detected in all experiments: The tendency to falsely remember new-similar items as being old increased with development, but so did the tendency to correctly remember them as being new-similar. (PsycINFO Database Record

Tobacco education in UK dental schools: A survey of current practice.

OBJECTIVE: To investigate the current provision of tobacco education (tobacco use and cessation), assessment and e-cigarette education in UK dental and dental hygiene and therapy (DHT) undergraduate programmes. MATERIALS AND METHODS: The study was conducted using a self-administered questionnaire sent to all UK institutions training dental and DHT students during the academic year 2015/2016. RESULTS: Twenty-five programmes returned completed questionnaires (response rate 68%). All programmes (100%) reported delivering tobacco education, delivered by multiple individuals in 78% of the programmes. Assessment of the theoretical and practical aspects of tobacco education was reported in 80% and 72% of the programmes, respectively. More formal teaching time was devoted to the theoretical aspects (100% >2 hours) rather than the practical aspects (76% > 2 hours) of tobacco education. All programmes expected their graduates to be clinically competent at discussing the health consequences of smoking, deliver a brief smoking cessation intervention, and referring patients to stop smoking services. The use of the National Centre for Smoking Cessation and Training "Very Brief Advice" (NCSCT VBA) training package was reported to be mandatory in 36%, and recommended, in 44% of programmes. Specialised stop smoking services delivered teaching in 40% of both dental and DHT training programmes whilst another 40% reported previous input from specialist smoking cessation services but not in 2015/2016. Most programmes reported delivery of teaching on electronic cigarettes, with 12% delivering a standalone lecture on this topic. CONCLUSIONS: Tobacco education is an important component of dental training. Dental education programmes should remain responsive to a rapidly changing field and fully utilise the available resources.

Overdistribution illusions: Categorical judgments produce them, confidence ratings reduce them.

Overdistribution is a form of memory distortion in which an event is remembered as belonging to too many episodic states, states that are logically or empirically incompatible with each other. We investigated a response formatting method of suppressing 2 basic types of overdistribution, disjunction and conjunction illusions, which parallel some classic illusions in the judgment and decision making literature. In this method, subjects respond to memory probes by rating their confidence that test cues belong to specific episodic states (e.g., presented on List 1, presented on List 2), rather than by making the usual categorical judgments about those states. The central prediction, which was derived from the task calibration principle of fuzzy-trace theory, was that confidence ratings should reduce overdistribution by diminishing subjects' reliance on noncompensatory gist memories. The data of 3 experiments agreed with that prediction. In Experiment 1, there were reliable disjunction illusions with categorical judgments but not with confidence ratings. In Experiment 2, both response formats produced reliable disjunction illusions, but those for confidence ratings were much smaller than those for categorical judgments. In Experiment 3, there were reliable conjunction illusions with categorical judgments but not with confidence ratings. Apropos of recent controversies over confidence-accuracy correlations in memory, such correlations were positive for hits, negative for correct rejections, and the 2 types of correlations were of equal magnitude. (PsycINFO Database Record

A Critical Role for Extracellular DNA in Dental Plaque Formation.

Extracellular DNA (eDNA) has been identified in the matrix of many different monospecies biofilms in vitro, including some of those produced by oral bacteria. In many cases, eDNA stabilizes the structure of monospecies biofilms. Here, the authors aimed to determine whether eDNA is an important component of natural, mixed-species oral biofilms, such as plaque on natural teeth or dental implants. To visualize eDNA in oral biofilms, approaches for fluorescently stained eDNA with either anti-DNA antibodies or an ultrasensitive cell-impermeant dye, YOYO-1, were first developed using Enterococcus faecalis, an organism that has previously been shown to produce extensive eDNA structures within biofilms. Oral biofilms were modelled as in vitro "microcosms" on glass coverslips inoculated with the natural microbial population of human saliva and cultured statically in artificial saliva medium. Using antibodies and YOYO-1, eDNA was found to be distributed throughout microcosm biofilms, and was particularly abundant in the immediate vicinity of cells. Similar arrangements of eDNA were detected in biofilms on crowns and overdenture abutments of dental implants that had been recovered from patients during the restorative phase of treatment, and in subgingival dental plaque of periodontitis patients, indicating that eDNA is a common component of natural oral biofilms. In model oral biofilms, treatment with a DNA-degrading enzyme, NucB from Bacillus licheniformis, strongly inhibited the accumulation of biofilms. The bacterial species diversity was significantly reduced by treatment with NucB and particularly strong reductions were observed in the abundance of anaerobic, proteolytic bacteria such as Peptostreptococcus, Porphyromonas and Prevotella. Preformed biofilms were not significantly reduced by NucB treatment, indicating that eDNA is more important or more exposed during the early stages of biofilm formation. Overall, these data demonstrate that dental plaque eDNA is potentially an important target for oral biofilm control.

Enlargement of the Internal Auditory Canal and Associated Posterior Fossa Anomalies in PHACES Association.

We noted enlargement of the internal auditory canal in several of our patients with posterior fossa malformations, hemangiomas, arterial anomalies, cardiac defects, eye abnormalities, and sternal or supraumbilical defects (PHACES) association and hence evaluated children with PHACES for the presence of an enlarged internal auditory canal and potential associated findings, including infantile hemangioma within the internal auditory canal, to understand the genesis of this enlargement. We reviewed our records to identify children with PHACES association who had been evaluated with MR imaging at our institutions. Imaging was reviewed for abnormal enhancement in the internal auditory canal, internal auditory canal enlargement, cerebellar hypoplasia, prominence of the petrous ridge, and deformity of the calvarium. We raise the possibility of an association between enlargement of the internal auditory canal in PHACES and a generalized malformation of the posterior fossa with cerebellar and calvarial hypoplasia.

Operator's ability at assessing a high-speed (air turbine) handpiece before use: an audit.

BACKGROUND: The 'high-speed' (air turbine) handpiece is used extensively across many dental disciplines and the ability of clinicians to detect faulty handpieces is essential. AIM: The primary aim of this audit was to determine the proportion of participants who could correctly identify unsafe handpieces. Secondary aims were to determine the proportion that had previous training on the topic and determine whether an educational video could improve scores. METHOD: Eighty participants completed the first round of audit. They were asked to inspect seven handpieces, five of which were faulty, with three being classed as unsafe. After the intervention (educational sessions and distribution of a video) a second round of audit was completed on 69 participants. RESULTS: The ability to detect the three unsafe handpieces increased from 10% to 44% over the two rounds of audit. In the second round the highest score obtained was by those who had received the intervention, 77%. The lowest score, 14%, was by those who had not received the intervention. Nine percent of participants in the first round stated they had previously had training on handpiece inspection and none of these participants identified the three unsafe handpieces. CONCLUSION: This audit has highlighted that there is a knowledge deficiency with regards to air turbine handpiece safety and inspection. We have shown that introduction of a simple education video can have an impact on dentists and students abilities to detect unsafe faults. We have already introduced this into the undergraduate curriculum in our school and we aim to also raise awareness within the dental community.

Outcomes of non-surgical periodontal treatment by dental hygienists in training: impact of site- and patient-level factors.

OBJECTIVES: To investigate the site- and patient-level factors that impact on the response to non-surgical periodontal therapy in patients with chronic periodontitis. METHODS: A retrospective evaluation of clinical outcomes following non-surgical periodontal therapy delivered by dental hygienists in training was undertaken. Case notes from 195 patients with chronic periodontitis were reviewed and clinical data pre- and post-treatment abstracted. Patients were categorized as 'responders' or 'non-responders' according to defined outcome criteria, and the relationship between clinical and demographic variables and treatment outcomes was assessed. RESULTS: Overall, there was a good response to the periodontal treatment. At deep sites (those with pretreatment probing depth ≥5 mm), the mean probing depth reduction was 1.6 ± 0.9 mm. Seventy-one (36%) patients were classified as non-responders (indicating that at least 30% of their deep sites did not improve by at least 2 mm following treatment). The non-responding group contained a significantly greater proportion of smokers (28%) than the responding group (16%). Plaque scores did not differ significantly between responders or non-responders either pre- or post-treatment. Regression analyses indicated that smoking status (odds ratio, OR: 2.04), mean pretreatment probing depth (OR: 1.49) and percentage of deep sites ≥5 mm at pretreatment (OR: 1.02) were significantly associated with response to treatment. CONCLUSION: This study supports the benefits of non-surgical therapy in the treatment of chronic periodontitis by dental hygienists in training. Better responses to treatment tend to be observed in non-smokers and in those with less advanced periodontitis at baseline.

Overdistribution in source memory.

Semantic false memories are confounded with a second type of error, overdistribution, in which items are attributed to contradictory episodic states. Overdistribution errors have proved to be more common than false memories when the 2 are disentangled. We investigated whether overdistribution is prevalent in another classic false memory paradigm: source monitoring. It is. Conventional false memory responses (source misattributions) were predominantly overdistribution errors, but unlike semantic false memory, overdistribution also accounted for more than half of true memory responses (correct source attributions). Experimental control of overdistribution was achieved via a series of manipulations that affected either recollection of contextual details or item memory (concreteness, frequency, list order, number of presentation contexts, and individual differences in verbatim memory). A theoretical model was used to analyze the data (conjoint process dissociation) that predicts that (a) overdistribution is directly proportional to item memory but inversely proportional to recollection and (b) item memory is not a necessary precondition for recollection of contextual details. The results were consistent with both predictions.